Friday, September 4, 2009

Supplement Philosophy

Not many supplements have done well against the placebo. Part of the problem is that there haven't been that many placebo controlled trials of supplements in humans. Another problem is that the supplements that have been tested, likely used incorrect doses or forms. That said, one cannot ignore the failure of E, C, beta carotene/A, selenium/E, and zinc against the placebo.

Also, one cannot ignore the findings of thousands of epidemiological studies finding inverse associations between cancer/other bad health outcomes and intakes of various nutrients. One way to thread the needle between the supplement studies and these nutrient studies would be to eat a healthy, whole food diet that is high in nutrients and take no supplements (aside from vitamin D, as discussed below). This approach can't be too far off the mark and might indeed be the most sensible.

However, this is not my approach. I suspect that the reason most supplement trials have failed is because they tested megadoses (and perhaps in the wrong nutrient forms). In the supplement world, more of something good is not better, after a point. In scientific lingo, this concept is known as the U-shaped dose response curve. My goal is to move myself closer to the sweet spot of the U-curve for those nutrients that are most associated with cancer prevention, specifically esophageal adenocarcinoma. To this end, I take low doses of most of my supplements, doses generally even lower than those found in most multivitamin pills. I also avoid certain nutrients that I think are better obtained solely through food (i.e., because I get enough from the many eggs I eat and because higher amounts have associated with worse health outcomes). I also base my decisions, in part, on the nutritional strengths and weaknesses of my particular diet, which can be determined using the chron-o-meter.

Vitamin D is a special situtation that warrants a separate discussion. I do take megadoses of vitamin D3, about 3000 IU per day or 7.5 x the RDA. We used to get vitamin D from the sun, but now we work inside all day, live in northern polluted cities, and generally avoid the sun. The current RDA is almost definitely too low. For instance, recently, a study showed that 1100 IUs of vitamin D3 per day resulted in a 77% reduction in risk of all cancers. I will discuss this study and vitamin D generally in the next post.

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